Organic light emitting display

ABSTRACT

Provided is an organic light emitting display comprising: a substrate including a light emitting zone and a non-light emitting zone, which is positioned around the outside of the light emitting zone; at least one organic light emitting diode formed on the light emitting zone; an encapsulation layer for sealing the organic light emitting diode; and a dam formed on the non-light emitting zone, wherein the encapsulation layer includes a structure in which at least one inorganic layer and at least one organic layer are alternatingly stacked, wherein the organic layer is made from a display sealing material composition, and wherein the display sealing material composition comprises a photo-curable monomer and a photopolymerization initiator. The photo-curable monomer comprises: a monomer not having an aromatic hydrocarbon group; and a monomer, represented by chemical formula 1, having at least two substituted or non-substituted phenyl groups, wherein the photo-curable monomer comprises approximately 5 wt. % to 45 wt. % of the monomer having the at least two substituted or non-substituted phenyl groups, and approximately 55 wt. % to 95 wt. % of a monomer not having the aromatic hydrocarbon group.

CROSS REFERENCE TO RELATED APPLICATIONS

This is the U.S. national phase application based on PCT Application No.PCT/KR2016/004593, filed May 2, 2016, which is based on Korean PatentApplication No. 10-2015-0087819, filed Jun. 19, 2015, the entirecontents of all of which are hereby incorporated by reference.

TECHNICAL FIELD

The invention relates to an organic light emitting display.

BACKGROUND ART

Organic light emitting elements are vulnerable to moisture and/oroxygen. Organic light emitting elements may suffer from delamination atan interface between a metal field and a light emitting layer due tomoisture. The organic light emitting elements may have high resistancedue to oxidation of metals and may suffer from degradation of organicmaterials in the light emitting layer due to moisture and/or oxygen. Theorganic light emitting element may suffer from deterioration in lightemission property due to oxidation of the light emitting layer or themetal field by outgassing inside or outside the organic light emittingelements. Thus, the organic light emitting element must be encapsulatedby an encapsulation composition capable of protecting the organic lightemitting element from moisture and/or oxygen.

The organic light emitting element may be encapsulated by anencapsulation layer having a multilayer structure in which an organiclayer and an inorganic layer are alternately stacked one above another.The inorganic layer may be formed by plasma deposition. However, theorganic layer may be etched by plasma. Etching may deteriorate anencapsulation function of the organic layer and provide adverseinfluence on formation of the inorganic layer. The organic layer isformed in contact with the inorganic layer. As a result, the organiclight emitting element may suffer from deterioration in light emittingproperty and reliability.

The organic layer may be formed by deposition or ink jetting. When thecorner of the organic layer is exposed to the corner of an encapsulationlayer without protection, an encapsulation property which protects theorganic light emitting element from moisture and/or oxygen may bedeteriorated. In addition, when the organic layer is formed by inkjetting, an encapsulation composition for an organic layer in a liquidstate may spread to a light emitting area or outside of a substrate,thereby thickening the edge of the encapsulation layer.

The background technique of the invention is disclosed in Korean PatentLaid-Open Publication No. 2011-0071039.

DISCLOSURE Technical Problem

It is one aspect of the invention to provide an organic light emittingdisplay device that includes an organic layer exhibiting high plasmaresistance.

It is another aspect of the invention to provide an organic lightemitting display device that includes an organic layer havingconsiderably low water vapor permeability and/or oxygen permeability.

It is a further aspect of the invention to provide an organic lightemitting display device that includes an organic layer exhibitingexcellent transparency.

It is yet another aspect of the invention to provide an organic lightemitting display device that includes an organic layer having lowsurface roughness and good surface flatness.

It is yet another aspect of the invention to provide an organic lightemitting display device that includes an organic layer capable ofsecuring reliability in elapsed time by protecting an organic lightemitting element from an external environment including moisture and/oroxygen.

It is yet another aspect of the invention to provide an organic lightemitting display device which may suppress an organic layer from beingexposed to outside of a light emitting area or a substrate and maysuppress an edge of the organic layer from being thickened.

Technical Solution

One aspect of the invention relates to an organic light emitting displaydevice including a substrate including a light emitting area and anon-light emitting area disposed outside of the light emitting area; atleast one organic light emitting element formed on the light emittingarea; an encapsulation layer encapsulating the organic light emittingelement; and a dam formed on the non-light emitting area, wherein theencapsulation layer has a structure in which at least one inorganiclayer and at least one organic layer are alternately stacked one aboveanother, and the organic layer includes a composition for encapsulatinga display device, the composition for encapsulating a display deviceincluding a photocurable monomer and a photopolymerization initiator,the photocurable monomer including a monomer without an aromatichydrocarbon; and a monomer of Formula 1 including substituted ornon-substituted at least two phenyl groups, the photocurable monomerincluding about 5 wt % to about 45 wt % of the monomer includingsubstituted or non-substituted at least two phenyl groups and about 55wt % to about 95 wt % of the monomer without an aromatic hydrocarbon.

wherein in Formula 1, A, Z¹, Z², a and b are as defined below.

Advantageous Effects

The invention provides an organic light emitting display device thatincludes an organic layer exhibiting high plasma resistance.

The invention provides an organic light emitting display device thatincludes an organic layer having considerably low water vaporpermeability and oxygen permeability.

The invention provides an organic light emitting display device thatincludes an organic layer exhibiting excellent transparency.

The invention provides an organic light emitting display device havinglow surface roughness and good surface flatness.

The invention provides an organic light emitting display device thatincludes an organic layer capable of securing reliability in elapsedtime by protecting an organic light emitting element from an externalenvironment including moisture and gas.

The invention provides an organic light emitting display device whichmay suppress an organic layer from being exposed to outside of a lightemitting area or a substrate and may suppress an edge of the organiclayer from being thickened.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic plan view of an organic light emitting displaydevice according to an embodiment of the invention.

FIG. 2 is a partial cross-sectional view of an organic light emittingdisplay device according to an embodiment of the invention.

FIG. 3 is a partial cross-sectional view of an organic light emittingdisplay device according to another embodiment of the invention.

FIG. 4 is a partial cross-sectional view of an organic light emittingdisplay device according to yet another embodiment of the invention.

FIG. 5 is a partial cross-sectional view of an organic light emittingdisplay device according to yet another embodiment of the invention.

BEST MODE

Hereinafter, embodiments of the invention will be described in detailwith reference to the accompanying drawings. It should be understoodthat the invention is not limited to the following embodiments and maybe embodied in different ways, and that the following embodiments aregiven to provide complete disclosure of the invention and to provide athorough understanding of the invention to those skilled in the art. Itshould be noted that the drawings are not to precise scale and some ofthe dimensions, such as width, length, thickness, and the like, areexaggerated for clarity of description in the drawings. Further,although only a portion of a component is illustrated for convenience ofdescription, other portions of the component can become apparent tothose skilled in the art. Furthermore, it should be understood that theinvention can be realized in various ways by those skilled in the artwithout departing from the spirit and scope of the invention.

As used herein, spatially relative terms such as “upper” and “lower” aredefined with reference to the accompanying drawings. Thus, it will beunderstood that “upper” can be used interchangeably with “lower”. Itwill be understood that when a layer is referred to as being “on”another layer, it can be directly formed on the other layer, orintervening layer(s) may also be present. Thus, it will be understoodthat when a layer is referred to as being “directly on” another layer,no intervening layer is interposed therebetween.

As used herein, the term “(meth)acryl” refers to acryl and/or methacryl.

Unless otherwise stated herein, the term “substituted” means that atleast one hydrogen atom in a functional group is substituted with ahydroxyl group, a nitro group, an imino group (═NH, ═NR, R being a C₁ toC₁₀ alkyl group), an amidino group, a hydrazine group, a hydrazonegroup, a carboxyl group, a C₁ to C₂₀ alkyl group, a C₆ to C₃₀ arylgroup, a C₃ to C₃₀ heteroaryl group, or a C₂ to C₃₀ heterocycloalkylgroup.

As used herein, the term “hetero atom” refers to an atom selected fromthe group consisting of N, O, S, and P, and the term “hetero” means thata carbon atom is substituted with an atom selected from the groupconsisting of N, O, S, and P.

As used herein, the term “plasma resistance” may be determined from anetch rate when a cured composition for encapsulation was treated withplasma, and a low etch rate is defined as a good plasma resistance.

As used herein, the term “alkylene group” refers to an alkanediyl grouphaving a saturated hydrocarbon without a double bond, and having twobonding groups.

As used herein, the term “alkoxylene group” refers to “—OR—” having twobonding groups, while R referring to an alkylene group.

As used herein, the terms “encapsulation” and “seal” refer tosurrounding an organic light emitting element and the terms havesubstantially the same meaning with each other.

The organic light emitting display device of the invention may include asubstrate including a light emitting area, and a non-light emitting areadisposed outside of the light emitting area; at least one organic lightemitting element formed on the light emitting area; an encapsulationlayer encapsulating the organic light emitting element; and a dam formedon the non-light emitting area, wherein the encapsulation layer has astructure in which at least one inorganic layer and at least one organiclayer are alternately stacked one above another, and the organic layerincludes a composition for encapsulating a display device.

The composition for encapsulating a display device according toembodiments of the invention may implement an organic layer having highplasma resistance and low surface roughness. In an organic lightemitting display device according to embodiments of the invention, anorganic layer is formed in contact with an inorganic layer. Thus, theorganic layer may flatten the inorganic layer and prevent defects of theinorganic layer, thereby preventing permeation of external moisture andoxygen. And a thin encapsulation layer may be formed.

The composition for encapsulating a display device according to theinvention may implement an organic layer having low water vaporpermeation and oxygen permeation. Therefore, the organic light emittingdisplay device of the invention may further inhibit permeation ofexternal moisture and/or oxygen into the organic light emitting elementand improve reliability in elapsed time of the organic light emittingelement.

The organic light emitting display device according to the invention mayinclude a dam. The dam may prevent corners of the organic layer frombeing exposed to outside. Therefore, the organic light emitting displaydevice of the invention may further suppress permeation of externalmoisture and/or oxygen into the organic light emitting element andincrease reliability in elapsed time of the organic light emittingelement.

The organic light emitting display device according to the invention mayinclude a dam. The dam may suppress the composition for encapsulationwhich is included in the organic layer from flowing to outside of alight emitting area or a substrate during formation of the organiclayer, thereby suppressing the organic layer from being formed outsideof the light emitting area or the substrate and also suppressingthickening of the edges of the organic layer.

For example, in the organic light emitting display device of theinvention, the inorganic layer may be additionally formed on the dam. Inan embodiment, the dam and the inorganic layer may be sequentiallyformed on the substrate. In another embodiment, the inorganic layer mayinclude a first inorganic layer and a second inorganic layer, and thedam, the first inorganic layer, and the second inorganic layer may besequentially formed on the substrate.

Further, in the organic light emitting display device of the invention,the encapsulation layer may be additionally formed on the dam. In anembodiment, the dam, the organic layer, and the inorganic layer may besequentially formed on the substrate. In another embodiment, theinorganic layer may include a first inorganic layer and a secondinorganic layer, and the organic layer may include a first organiclayer. The dam, the first inorganic layer, the first organic layer, andthe second inorganic layer may be sequentially formed on the substrate.

In addition, in the organic light emitting display device of theinvention, the first organic layer in the light emitting area may beseparated from the first organic layer in the non-light emitting area bythe dam.

Hereinafter, an organic light emitting display device according to anembodiment of the invention will be explained with reference to FIGS. 1and 2. FIG. 1 is a schematic plan view of an organic light emittingdisplay device according to an embodiment of the invention. FIG. 2 is apartial cross-sectional view of an organic light emitting display deviceaccording to an embodiment of the invention.

Referring to FIG. 1, an organic light emitting display device 100according to an embodiment of the invention may include a substrate 110,a dam 140, and a light emitting area 100 a. The substrate 110 mayinclude a light emitting area 100 a in which at least one organic lightemitting element is formed and a non-light emitting area in which thedam 140 is formed and is located outside of the light emitting area 100a.

Referring to FIG. 2, an organic light emitting display device 100according to one embodiment may include a substrate 110, an organiclight emitting element 120, an encapsulation layer 130, and a dam 140.

The substrate 110 may be disposed under the organic light emittingelement 120, the encapsulation layer 130, and the dam 140 to support theorganic light emitting element 120, the encapsulation layer 130, and thedam 140. The substrate 110 may include a light emitting area in which atleast one organic light emitting element 120 is formed, and a non-lightemitting area in which the dam 140 is formed and is located outside ofthe light emitting area.

The substrate 110 may be a glass substrate, a quartz substrate, or atransparent plastic substrate. The transparent plastic substrate may beapplied to flexible products by providing flexibility to the organiclight emitting display device. The transparent plastic substrate may beformed of at least one of a polyimide resin, an acrylic resin, apolyacrylate resin, a polycarbonate resin, a polyether resin, apolyester resin including polyethylene terephthalate, and a sulfonicacid resin, without being limited thereto.

The organic light emitting element 120 may be formed on the lightemitting area of the substrate 110 to drive the organic light emittingdisplay device 100. The organic light emitting element 120 is aself-emissive device and may include a typical structure known to thoseskilled in the art.

Specifically, the organic light emitting element 120 may have astructure in which an anode, a hole transport region, a light emittinglayer, an electron transport region, and a cathode are sequentiallystacked in this order. The hole transport region may include at leastone of a hole injection layer, a hole transport layer, and an electronblocking layer. The electron transport region may include at least oneof a hole blocking layer, an electron transport layer, and an electroninjection layer. Light is emitted from the light emitting layer throughrecombination of holes generated from the anode and electrons generatedfrom the cathode in the light emitting layer. Details of the anode, thehole transport region, the light emitting layer, the electron transportregion, and the cathode are well known to those skilled in the art.

Specifically, the anode may include a material having high work functionto allow efficient injection of holes into the light emitting layer.Examples of materials for the anode may include metals such as nickel,platinum, vanadium, chromium, copper, zinc, and gold, metal alloysthereof, metal oxides such as zinc oxide, indium oxide, indium tinoxide, and indium zinc oxide, combinations of metals and metal oxides,such as a combination of zinc oxide and aluminum, a combination of zincoxide and antimony. The cathode may include a material having low workfunction to allow easy injection of electrons into an organic lightemitting layer. Examples of materials for the cathode may include metalssuch as magnesium, calcium, sodium, potassium, titanium, indium,yttrium, lithium, gadolinium, aluminum, silver, tin, lead, cesium,barium, or metal alloys thereof.

The light emitting layer may include a material known to those skilledin the art. For example, the light emitting layer may include fluorenederivatives and metal complexes, without being limited thereto.

The hole transport region may include a material such as m-MTDATA,TDATA, 2-TNATA, NPB, β-NPB, TPD, Spiro-TPD, Spiro-NPB, α-NPB, TAPC,HMTPD, PEDOTT/PSS(poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate), and PANT/PSS(polyaniline/poly(4-styrenesulfonate) as follows, without being limitedthereto.

The hole blocking layer may include at least one of BCP and Bphen asfollows, without being limited thereto.

The electron transport layer may include at least one of BCP and Bphenas above, and Alq₃, BAlq, TAZ, NTAZ, ET1, and ET2 as follows, withoutbeing limited thereto.

The electron injection layer may include at least one of LiF, NaCl, CsF,Li₂O, and BaO, without being limited thereto.

The encapsulation layer 130 may be directly formed on the organic lightemitting element 120. The encapsulation layer 130 may encapsulate theorganic light emitting element 120. As used herein, the expression“directly formed on” means that no adhesive layer, bonding layer and/orair layer is interposed between the encapsulation layer 130 and theorganic light emitting element 120.

The encapsulation layer 130 may have a multilayer structure in which atleast one inorganic layer and at least one organic layer are alternatelystacked one above another. FIG. 2 shows an organic light emittingdisplay device 100 including an encapsulation layer 130 in which twoinorganic layers and one organic layer are alternately stacked in atotal of three layers. Specifically, FIG. 2 shows an organic lightemitting display device 100 including an encapsulation layer 130 inwhich a first inorganic layer 131, a first organic layer 132, and asecond inorganic layer 133 are alternately stacked one above another. Inother embodiments, the encapsulation layer may have other types ofmultilayer structure in which the inorganic layers and the organiclayers are alternately stacked in a total of 5 to 15 layers,specifically 5 to 7 layers. For example, in the structure in which theencapsulation layer includes a total of 5 layers, the encapsulationlayer may include a first inorganic layer, a first organic layer, asecond inorganic layer, a second organic layer, and a third inorganiclayer alternately stacked one above another. In the structure in whichthe encapsulation layer includes a total of 7 layers, the encapsulationlayer may include a first inorganic layer, a first organic layer, asecond inorganic layer, a second organic layer, a third inorganic layer,a third organic layer, and a fourth inorganic layer sequentiallystacked. The inorganic layer or the organic layer of the encapsulationlayer 130 is directly formed on the organic light emitting element 120to encapsulate the organic light emitting element 120. The outermostlayer of the encapsulation layer 130 may be an inorganic layer.

Hereinafter, an encapsulation layer 130 in which a first inorganic layer131, a first organic layer 132, and a second inorganic layer 133 aresequentially stacked will be explained with reference to FIG. 2.

Components of the first inorganic layer 131 and the second inorganiclayer 133 may be different from the component of the first organic layer132, and may complement the effect of the first organic layer 132. Thefirst inorganic layer 131 and the second inorganic layer 133 each maysuppress permeation of moisture and/or oxygen into the organic lightemitting element 120. The outermost layer of the encapsulation layer 130with respect to the organic light emitting element 120 may be aninorganic layer that is the second inorganic layer 133.

The first inorganic layer 131 may be directly formed on the organiclight emitting element 120, and may encapsulate the organic lightemitting element 120. The first inorganic layer 131 may be additionallyformed on the dam 140.

The first inorganic layer 131 may be formed in direct contact with theorganic light emitting element 120 and the dam 140. The “formed indirect” means that no adhesive layer, bonding layer and/or air layer isinterposed between the organic light emitting element 120 and the firstinorganic layer 131, and between the dam 140 and the first inorganiclayer 131. A portion the first inorganic layer 131 directly formed onthe organic light emitting element 120 and a portion of the firstinorganic layer 131 directly formed on the dam 140 are integrallyformed. As used herein, the term “integrally formed” means that thecorresponding portions are formed in one layer without beingindependently separated from each other. Thus, the first inorganic layer131 may reduce permeation of external moisture and/or oxygen into theorganic light emitting element 120.

The second inorganic layer 133 may be formed on the organic lightemitting element 120 to encapsulate the organic light emitting element120. The second inorganic layer 133 may be additionally formed on thedam 140.

The second inorganic layer 133 may be directly formed on the firstorganic layer 132. The first organic layer 132 may include a compositionfor encapsulating a display device according to embodiments of theinvention. Thus, the second inorganic layer 133 may have low surfaceroughness and good flatness to implement a thin encapsulation layer 130.

The second inorganic layer 133 may be directly formed on the firstinorganic layer 131 which is formed on the dam 140. Thus, the secondinorganic layer 133 is integrally formed as the first inorganic layer131 is integrally formed. The second inorganic layer 133 may furthersuppress permeation of external moisture and/or oxygen into the organiclight emitting element 120, and may reduce slight lifting and/ordelamination between the first inorganic layer 131 and the secondinorganic layer 133. Therefore, the organic light emitting displaydevice 100 according to the embodiment may have a structure in which thedam 140, the first inorganic layer 131, and the second inorganic layer133 are sequentially formed on the substrate 110.

In addition, as shown in FIG. 4, it is also possible to form a firstorganic layer 132 directly on an organic light emitting element 120 andthen form a first inorganic layer 131 thereon, thereby implementing athinner encapsulation layer 130″.

Each of the first inorganic layer 131 and the second inorganic layer 133may include an inorganic material having good light transmittance. Thefirst inorganic layer 131 and the second inorganic layer 133 may beformed of the same or different inorganic materials. Specifically, theinorganic materials may include metals, nonmetals, intermetalliccompounds or alloys, inter non-metallic compounds or alloys, oxides ofmetals or nonmetals, fluorides of metals or nonmetals, nitrides ofmetals or nonmetals, carbides of metals or nonmetals, oxynitrides ofmetals or nonmetals, borides of metals or nonmetals, oxyborides ofmetals or nonmetals, silicides of metals or nonmetals, and mixturesthereof. The metals or nonmetals may include silicon (Si), aluminum(Al), selenium (Se), zinc (Zn), antimony (Sb), indium (In), germanium(Ge), tin (Sn), bismuth (Bi), transition metals, and lanthanide metals,without being limited thereto. Specifically, the first inorganic layerand the second inorganic layer may each include silicon oxide (SiOx),silicon nitride (SiNx), silicon oxynitride (SiOxNy), ZnSe, ZnO, Sb₂O₃,AlOx including Al₂O₃, In₂O₃, or SnO₂. Here, each of x and y ranges from1 to 5.

The first inorganic layer 131 and the second inorganic layer 133 mayhave the same or different thickness. For example, the first inorganiclayer 131 and the second inorganic layer 133 each may have a thicknessof about 40 nm to about 1,000 nm, specifically about 100 nm to about1,000 nm. Within this range, the inorganic layer may prevent permeationof external moisture and/or oxygen.

The first organic layer 132 may be directly formed on the firstinorganic layer 131 encapsulating the organic light emitting element120, and may be formed between the first inorganic layer 131 and thesecond inorganic layer 133. The first organic layer 132 may encapsulatethe organic light emitting element 120 to suppress permeation ofexternal moisture and/or oxygen into the organic light emitting element120. Also, the first organic layer 132 has a low plasma etch rate andlow surface roughness, which enables to form a second inorganic layer133 in a constant thickness.

The first organic layer 132 may have a thickness of about 0.2 μm toabout 15 μm, for example about 1 μm to about 15 μM. Within this range,the organic layer may flatten an inorganic layer and prevent defects ofthe inorganic layer, thereby preventing permeation of external moistureand oxygen.

The first organic layer 132 may include a composition for encapsulatinga display device according to embodiments of the invention.

Hereinafter, a composition for encapsulating a display device accordingto embodiments of the invention will be described.

The composition for encapsulating a display device according to anembodiment of the invention may include a photocurable monomer and aphotopolymerization initiator.

The photocurable monomer may mean a photocurable monomer which mayundergo a curing reaction by the photopolymerization initiator. Anon-silicon based monomer which does not include silicon (Si) may beused as the photocurable monomer. For example, the photocurable monomermay be a monomer formed only of at least one element selected from thegroup consisting of C, H, O, N or S, without being limited thereto. Thephotocurable monomer may be synthesized by conventional syntheticmethods, or a commercial product may be used.

The photocurable monomer may include a monomer without an aromatichydrocarbon (non-aromatic hydrocarbon based monomer); and a monomer offollowing Formula 1 including substituted or non-substituted at leasttwo phenyl groups, and the photocurable monomer may include about 5 wt %to about 45 wt % of the monomer including substituted or non-substitutedat least two phenyl groups and about 55 wt % to about 95 wt % of themonomer without an aromatic hydrocarbon:

wherein in Formula 1, A is a hydrocarbon including substituted ornon-substituted at least two phenyl groups, or a hetero atom-containinghydrocarbon including substituted or non-substituted at least two phenylgroups,

Z¹ and Z² are each independently a compound of following Formula 2,

a and b are each independently an integer of 0 to 2, and a+b is aninteger of 1 to 4:

wherein in Formula 2, * is a portion connected to a carbon atom of A inFormula 1,

X is a single bond, O or S,

Y is a substituted or non-substituted straight chain alkylene grouphaving 1 to 10 carbon atoms, or a substituted or non-substitutedalkoxylene group having 1 to 20 carbon atoms,

R¹ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and

c is 0 or 1.

In Formula 2, the term “single bond” means that A of Formula 1 isdirectly connected to (Y)c without any interposing element therebetween.

In the above Formula 1, A is a hydrocarbon including substituted ornon-substituted at least two phenyl groups, or a hetero atom-containinghydrocarbon including substituted or non-substituted at least two phenylgroups. The hydrocarbon including substituted or non-substituted atleast two phenyl groups, or the hetero atom-containing hydrocarbonincluding substituted or non-substituted at least two phenyl groups maymean that the substituted or non-substituted at least two phenyl groupsare not condensed and are bonded to a single bond, an oxygen atom, asulfur atom, a substituted or non-substituted alkylene group having 1 to5 carbon atoms, a hetero atom-substituted or non-substituted alkylenegroup having 3 to 6 carbon atoms, an ethenylene group, an ethynylenegroup, or a carbonyl group. Examples of the hydrocarbon includingsubstituted or non-substituted at least two phenyl groups, or thehydrocarbon including a substituted or non-substituted hetero atomincluding at least two phenyl groups may include a substituted ornon-substituted biphenyl group, a substituted or non-substitutedtriphenylmethyl group, a substituted or non-substituted terphenyl group,a substituted or non-substituted biphenylene group, a substituted ornon-substituted terphenylene group, a substituted or non-substitutedquarterphenylene group, a substituted or non-substituted2-phenyl-2-(phenylthio)ethyl group, a substituted or non-substituted2,2-diphenylpropane group, a substituted or non-substituteddiphenylmethane group, a substituted or non-substituted cumylphenylgroup, a substituted or non-substituted bisphenol F group, a substitutedor non-substituted bisphenol A group, a substituted or non-substitutedbiphenyloxy group, a substituted or non-substituted terphenyloxy group,a substituted or non-substituted quarterphenyloxy group, a substitutedor non-substituted quinquephenyloxy group, and structural isomersthereof, without being limited thereto.

The monomer including substituted or non-substituted at least two phenylgroups may include mono(meth)acrylate, di(meth)acrylate, or mixturesthereof. Examples of the monomer including substituted ornon-substituted at least two phenyl groups may include4-(meth)acryloxy-2-hydroxybenzophenone, ethyl-3,3-diphenyl(meth)acrylate, benzoyloxyphenyl(meth)acrylate, bisphenol A di(meth)acrylate,ethoxylated bisphenol A di(meth)acrylate, bisphenol F di(meth)acrylate,ethoxylated bisphenol F di(meth)acrylate,4-cumylphenoxyethyl(meth)acrylate, ethoxylatedbisphenylfluorenedi(meth)acrylate, 2-phenylphenoxyethyl(meth)acrylate,2,2′-phenylphenoxyethyldi(meth)acrylate,2-phenylphenoxypropyl(meth)acrylate,2,2′-phenylphenoxypropyldi(meth)acrylate,2-phenylphenoxybutyl(meth)acrylate,2,2′-phenylphenoxybutyldi(meth)acrylate,2-(3-phenylphenyl)ethyl(meth)acrylate,2-(4-benzylphenyl)ethyl(meth)acrylate,2-phenyl-2-(phenylthio)ethyl(meth)acrylate,2-(triphenylmethyloxy)ethyl(meth)acrylate,4-(triphenylmethyloxy)butyl(meth)acrylate,3-(biphenyl-2-yloxy)butyl(meth)acrylate,2-(biphenyl-2-yloxy)butyl(meth)acrylate,4-(biphenyl-2-yloxy)propyl(meth)acrylate,3-(biphenyl-2-yloxy)propyl(meth)acrylate, 2-(biphenyl-2-yloxy)propyl(meth)acrylate, 4-(biphenyl-2-yloxy)ethyl(meth)acrylate,3-(biphenyl-2-yloxy)ethyl (meth)acrylate,2-(4-benzylphenyl)ethyl(meth)acrylate, 4,4′-di((meth)acryloyloxymethyl)biphenyl, 2,2′-di(2-(meth)acryloyloxyethoxy)biphenyl,structural isomers thereof, or mixtures thereof, without being limitedthereto. In addition, (meth)acrylate mentioned in the invention is anexample without being limited to only those in the example, and theinvention also includes acrylates which are structural isomers of(meth)acrylate. For example, although2,2′-phenylphenoxyethyldi(meth)acrylate is mentioned as an example, theinvention may also include 3,2′-phenylphenoxyethyldi(meth)acrylate,3,3′-phenylphenoxyethyldi(meth)acrylate and the like, which arestructural isomers of 2,2′-phenylphenoxyethyldi(meth)acrylate.

In some embodiments, the monomer including substituted ornon-substituted at least two phenyl groups may includemono(meth)acrylate represented by following Formula 3:

wherein in Formula 3, R² is hydrogen or a methyl group, R³ is asubstituted or non-substituted straight chain alkylene group having 1 to10 carbon atoms, or a substituted or non-substituted alkoxylene grouphaving 1 to 20 carbon atoms, and R⁴ is a hydrocarbon includingsubstituted or non-substituted at least two phenyl groups, or a heteroatom-containing hydrocarbon including substituted or non-substituted atleast two phenyl groups.

For example, the hydrocarbon including substituted or non-substituted atleast two phenyl groups, or the hetero atom-containing hydrocarbonincluding substituted or non-substituted at least two phenyl groups maymean that the substituted or non-substituted at least two phenyl groupsare not condensed and are bonded to a single bond, an oxygen atom, asulfur atom, a substituted or non-substituted alkylene group having 1 to3 carbon atoms, a hetero atom-substituted or non-substituted alkylenegroup having 3 to 6 carbon atoms, an ethenylene group, an ethynylenegroup, or a carbonyl group. Examples of the hydrocarbon includingsubstituted or non-substituted at least two phenyl groups, or thehetero-atom containing hydrocarbon including substituted ornon-substituted at least two phenyl groups may include a substituted ornon-substituted biphenyl group, a substituted or non-substitutedtriphenylmethyl group, a substituted or non-substituted terphenyl group,a substituted or non-substituted biphenylene group, a substituted ornon-substituted terphenylene group, a substituted or non-substitutedquarterphenylene group, a substituted or non-substituted2-phenyl-2-(phenylthio)ethylene group, a substituted or non-substituted2,2-diphenylpropane group, a substituted or non-substituteddiphenylmethane group, a substituted or non-substituted cumylphenylgroup, a substituted or non-substituted bisphenol F group, a substitutedor non-substituted bisphenol A group, a substituted or non-substitutedbiphenyloxy group, a substituted or non-substituted terphenyloxy group,a substituted or non-substituted quarterphenyloxy group, a substitutedor non-substituted quinquephenyloxy group, and the like, without beinglimited thereto.

In some embodiments, the monomer including substituted ornon-substituted at least two phenyl groups may include di(meth)acrylaterepresented by following Formula 4:

wherein in Formula 4, R⁵ and R⁹ are each independently hydrogen or amethyl group, R⁶ and R⁸ are each independently a substituted ornon-substituted straight chain alkylene group having 1 to 10 carbonatoms, or a substituted or non-substituted alkoxylene group having 1 to20 carbon atoms, and R⁷ is a hydrocarbon including substituted ornon-substituted at least two phenyl groups, or a hetero atom-containinghydrocarbon including substituted or non-substituted at least two phenylgroups.

For example, the hydrocarbon including substituted or non-substituted atleast two phenyl groups, or the hetero atom-containing hydrocarbonincluding substituted or non-substituted at least two phenyl groups maymean that the substituted or non-substituted at least two phenyl groupsare not condensed and are bonded to a single bond, an oxygen atom, asulfur atom, a substituted or non-substituted alkylene group having 1 to4 carbon atoms, a hetero atom-substituted or non-substituted alkylenegroup having 3 to 6 carbon atoms, an ethenylene group, an ethynylenegroup, or a carbonyl group. Examples of the hydrocarbon includingsubstituted or non-substituted at least two phenyl groups, or the heteroatom-containing hydrocarbon including substituted or non-substituted atleast two phenyl groups may include a substituted or non-substitutedbiphenylene group, a substituted or non-substituted triphenylmethylenegroup, a substituted or non-substituted terphenylene group, asubstituted or non-substituted quarterphenylene group, a2-phenyl-2-(phenylthio)ethylene group, a 2,2-diphenylpropylene group, adiphenylmethylene group, and the like, without being limited thereto.

In Formula 1, a and b are each independently an integer of 0 to 2, anda+b is an integer of 1 to 4. In some embodiments, a+b is 1 or 2.

The monomer including substituted or non-substituted at least two phenylgroups may have a molecular weight of about 100 g/mol to about 1,000g/mol, about 130 g/mol to about 700 g/mol, about 150 g/mol to about 600g/mol. Within this range, an organic layer having good plasmaresistance, low surface roughness, and excellent transmittance may beprovided.

The monomer including substituted or non-substituted at least two phenylgroups may be present in an amount of about 5 wt % to about 45 wt %, forexample about 10 wt % to about 40 wt %, based on a total weight of thephotocurable monomer. Within this range, an organic layer having asuitable viscosity for forming an organic layer and good plasmaresistance may be produced.

The monomer without an aromatic hydrocarbon group does not include anaromatic hydrocarbon, and may include a monomer having about 1 to about20, for example about 1 to about 6 photocurable functional groups atleast one selected from a vinyl group, an acrylate group, and amethacrylate. The non-aromatic hydrocarbon based monomer may includeabout 1 to about 3, for example about 1 to about 2, about 1, or about 2photocurable functional group.

The monomer without an aromatic hydrocarbon may have a molecular weightof about 100 g/mol to about 500 g/mol, about 130 g/mol to about 400g/mol. Within this range, more advantageous effects in terms ofprocessability may be exhibited.

The monomer without an aromatic hydrocarbon may include a monofunctionalmonomer with a photocurable functional group, a polyfunctional monomerwith a photocurable functional group, or mixtures thereof.

The monomer without an aromatic hydrocarbon group may include a (meth)acrylate monomer. Examples of the non-aromatic hydrocarbon based monomermay include unsaturated carboxylic acid ester including an alkyl grouphaving 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbonatoms, a hydroxyl group, and an alkyl group having 1 to 20 carbon atoms;unsaturated carboxylic acid ester including an aminoalkyl group having 1to 20 carbon atoms; vinyl ester of saturated or unsaturated carboxylicacid having 1 to 20 carbon atoms; a vinyl cyanide compound; anunsaturated amide compound; monofunctional or multi-functional (meth)acrylate of monohydric or polyhydric alcohol and the like. The term“polyhydric alcohol” may mean an alcohol including at least two, forexample about 2 to about 20, specifically about 2 to about 10, morespecifically about 2 to about 6 hydroxyl groups.

In some embodiments, examples of the (meth) acrylate monomer without anaromatic hydrocarbon may include mono(meth)acrylate, di(meth)acrylate,tri(meth)acrylate, tetra(meth)acrylate and the like including asubstituted or non-substituted C₁ to C₂₀ alkyl group, a substituted ornon-substituted C₁ to C₂₀ alkylsilyl group, a substituted ornon-substituted C₃ to C₂₀ cycloalkyl group, a substituted ornon-substituted C₁ to C₂₀ alkylene group, an amine group, an ethyleneoxide group.

Examples of the (meth) acrylate monomer without an aromatic hydrocarbongroup may include unsaturated carboxylic acid ester including (meth)acrylic acid ester such as methyl (meth)acrylate, ethyl (meth)acrylate,butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl(meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, nonyl(meth)acrylate, decanyl (meth)acrylate, undecanyl (meth)acrylate,dodecyl (meth)acrylate, cyclohexyl (meth)acrylate and the like;unsaturated carboxylic acid aminoalkyl ester such as 2-aminoethyl(meth)acrylate, 2-dimethylaminoethyl (meth)acrylate and the like;saturated or unsaturated carboxylic acid vinyl ester such as vinylacetate and the like; a vinyl cyanide compound such as(meth)acrylonitrile; an unsaturated amide compound such as(meth)acrylamide; ethylene glycol di(meth)acrylate, triethylene glycoldi(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,4-butanedioldi(meth)acrylate, 1,6-hexanediol di(meth)acrylate, octanedioldi(meth)acrylate, nonanediol di(meth)acrylate, decanedioldi(meth)acrylate, undecanediol di(meth)acrylate, dodecanedioldi(meth)acrylate, neopentylglycol di(meth)acrylate, pentaerythritoldi(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol di(meth)acrylate,dipentaerythritol tri(meth)acrylate, dipentaerythritoltetra(meth)acrylate, dipentaerythritol penta(meth)acrylate,dipentaerythritol hexa(meth)acrylate, or mixtures thereof, without beinglimited thereto.

In some embodiments, the monomer without an aromatic hydrocarbon may bea non-aromatic based compound which does not include an aromatic group,and examples of the monomer without an aromatic hydrocarbon may includeat least one of mono(meth)acrylate including a substituted ornon-substituted alkyl group having 1 to 20 carbon groups,mono(meth)acrylate including an amine group, di(meth)acrylate includinga substituted or non-substituted alkylene group having 1 to 20 carbongroups, di(meth)acrylate including an ethylene oxide group,tri(meth)acrylate including an ethylene oxide group, ortrimethylolpropane tri(meth)acrylate.

Examples of the mono(meth)acrylate compound including a substituted ornon-substituted alkyl group having 1 to 20 carbon atoms may includedecyl(meth)acrylate, undecyl(meth)acrylate, lauryl(meth)acrylate,tridecyl(meth)acrylate, tetradecyl(meth)acrylate,pentadecyl(meth)acrylate, hexadecyl(meth)acrylate,heptadecyl(meth)acrylate, octadecyl(meth)acrylate,nonadecyl(meth)acrylate, arachidyl(meth)acrylate, or mixtures thereof,without being limited thereto.

Examples of the mono(meth)acrylate compound including an amine group mayinclude 2-aminoethyl(meth)acrylate, 2-dimethylaminoethyl(meth)acrylate,or mixtures thereof, without being limited thereto.

Examples of the di(meth)acrylate compound including a substituted ornon-substituted alkylene group having 1 to 20 carbon atoms may includedi(meth)acrylate including an alkylene group having 1 to 20 carbonatoms, non-silicon based di(meth)acrylate including a substituted ornon-substituted long chain alkylene group. When the non-silicon baseddi(meth)acrylate including a long chain alkylene group is included inthe composition, the composition for encapsulation may easily form anorganic layer on an organic light emitting element, or on an inorganiclayer encapsulating an organic light emitting element. Examples ofdi(meth)acrylate including a substituted or non-substituted alkylenegroup having 1 to 20 carbon atoms may include octanedioldi(meth)acrylate, nonanediol di(meth)acrylate, decanedioldi(meth)acrylate, undecanediol di(meth)acrylate, dodecanedioldi(meth)acrylate, or mixtures thereof, without being limited thereto.When di(meth)acrylate including a substituted or non-substitutedalkylene group having 1 to 20 carbon atoms is included in thecomposition, the composition for encapsulation may have lower photocuring rate and low viscosity.

Examples of the di(meth)acrylate compound including an ethylene oxidegroup or tri(meth)acrylate including an ethylene oxide group may includeethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate,or mixtures thereof, without being limited thereto.

The monomer without an aromatic hydrocarbon may be present in an amountof about 55 wt % to about 95 wt %, for example about 60 wt % to about 90wt %, based on a total weight of the photocurable monomer. Within thisrange, the composition for encapsulating a display device may have asuitable viscosity for forming an organic layer.

The photocurable monomer includes a monomer without an aromatichydrocarbon (a non-aromatic hydrocarbon-based monomer) and a monomerincluding substituted or non-substituted at least two phenyl group ofFormula 1 above, and the photocurable monomer may be present in anamount of about 80 to about 99.9 parts by weight in the composition forencapsulating a display device, based on 100 parts by weight of a totalweight of the photocurable monomer and the photopolymerizationinitiator. Within this range, the effect of the invention may beimplemented. For example, the photocurable monomer may be present in anamount of about 90 to about 99.5 parts by weight, specifically about 92to about 99 parts by weight.

The photopolymerization initiator may cure the monomer without anaromatic hydrocarbon and the monomer including substituted ornon-substituted at least two phenyl groups.

The photopolymerization initiator may include a typicalphotopolymerization initiator which may carry out a photopolymerizationreaction, without limitation. For example, the photopolymerizationinitiator may include a triazine initiator, an acetophenone initiator, abenzophenone initiator, a thioxanthone initiator, a benzoin initiator, aphosphorus initiator, an oxime initiator, or mixtures thereof.

Examples of the triazine initiator may include2,4,6-trichloro-s-triazine,2-phenyl-4,6-bis(trichloromethyl)-s-triazine,2-(3′,4′-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine,2-(4′-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine,2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine,2-biphenyl-4,6-bis(trichloromethyl)-s-triazine,bis(trichloromethyl)-6-styryl-s-triazine,2-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2,4-trichloromethyl(piperonyl)-6-triazine,2,4-trichloromethyl(4′-methoxystyryl)-6-triazine, or mixtures thereof.

Examples of the acetophenone initiator may include2,2′-diethoxyacetophenone, 2,2′-dibutoxyacetophenone,2-hydroxy-2-methylpropiophenone, p-t-butyl trichloroacetophenone,p-t-butyl dichloroacetophenone, 4-chloroacetophenone,2,2′-dichloro-4-phenoxyacetophenone,2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropan-1-one2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, or mixturesthereof.

Examples of the benzophenone initiator may include benzophenone, benzoylbenzoic acid, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, acrylated benzophenone,4,4′-bis(dimethylamino)benzophenone, 4,4′-dichloro benzophenone,3,3′-dimethyl-2-methoxy benzophenone, or mixtures thereof.

Examples of the thioxanthone initiator may include thioxanthone,2-methyl thioxanthone, isopropyl thioxanthone, 2,4-diethyl thioxanthone,2,4-diisopropyl thioxanthone, 2-chlorothioxanthone, or mixtures thereof.

Examples of the benzoin initiator may include benzoin, benzoin methylether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutylether, benzyl dimethyl ketal, or mixtures thereof.

Examples of the phosphorus initiator may include bisbenzoylphenylphosphine oxide, trimethylbenzoyldiphenyl phosphine oxide, or mixturesthereof.

Examples of the oxime initiator may include2-(o-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione,1-(o-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone,or mixtures thereof.

It is also possible to use a photo acid generator or aphotopolymerization initiator such as carbazole, diketone, sulfonium,iodonium, diazo, biimidazole based compounds in place of the abovementioned photopolymerization initiator.

The photopolymerization initiator may be present in an amount of about0.1 to about 20 parts by weight in the composition for encapsulating adisplay device, based on 100 parts by weight of a total weight of thephotocurable monomer and the photopolymerization initiator. Within thisrange, a photopolymerization reaction may take place sufficiently whenexposed to a light, and transmittance deterioration caused by anunreacted initiator after the photopolymerization reaction may beprevented. In an implementation, the photopolymerization initiator maybe present in an amount of about 0.5 to about 10 parts by weight, forexample about 1 to about 8 parts by weight. In addition, thephotopolymerization initiator may be present in an amount of about 0.1wt % to about 10 wt %, for example about 0.1 wt % to about 8 wt % in thecomposition for encapsulating a display device. Within this range, aphoto polymerization reaction may take place sufficiently, andtransmittance deterioration caused by an unreacted initiator may beprevented.

A composition for encapsulating a display device according to anotherembodiment of the invention may include a photocurable monomer, a photopolymerization initiator, and an antioxidant. This composition issubstantially the same with the above explained composition forencapsulating a display device according to an embodiment of theinvention except for further including an antioxidant.

An antioxidant may improve thermal stability of the encapsulation layer.The antioxidant may include at least one selected from the groupconsisting of phenol, quinone, amine, and phosphite, without beinglimited thereto. For example, the antioxidant may includetetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane,tris(2,4-di-tert-butylphenyl)phosphite and the like.

The antioxidant may be present in an amount of about 0.01 to about 3parts by weight, for example about 0.01 to about 1 parts by weight inthe composition for encapsulating a display device, based on 100 partsby weight of a total weight of the photocurable monomer and thephotopolymerization initiator. Within this range, the organic layer mayexhibit excellent thermal stability.

A composition for encapsulating a display device according to yetanother embodiment of the invention may include a photocurable monomer,a photo polymerization initiator, and a heat stabilizer. Thiscomposition is substantially the same with the above explainedcomposition for encapsulating a display device according to anembodiment of the invention except for except for further including aheat stabilizer. By including the heat stabilizer, a viscosity change ofthe composition for encapsulating a display device according to yetanother embodiment of the invention may be suppressed at roomtemperature. Further, it is possible to increase a light transmissionrate and a photocuring rate, and to lower a plasma etch rate, ascompared with a composition for encapsulation without a heat stabilizer.Since this composition is substantially the same with the compositionfor encapsulating a display device according to an embodiment of theinvention except for further including a heat stabilizer, only the heatstabilizer will be explained below.

The heat stabilizer may inhibit a viscosity change of a composition forencapsulation at room temperature, and a conventional heat stabilizermay be used without limitation. For example, a sterically hinderedphenolic heat stabilizer may be used. Specifically, the heat stabilizermay include at least one of poly(dicyclopentadiene-co-p-cresol),octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,2,6-di-tert-butyl-4-methylphenol,2,2′-metano-bi(4-methyl-6-tert-butyl-phenol),6,6′-di-tert-butyl-2,2′-thiodi-p-cresol,tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, triethyleneglycol-bis(3-tert-butyl-4-hydroxy-5-methylphenyl),4,4′-thiobis(6-tert-butyl-m-cresol),3,3′-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-N,N′-hexamethylene-dipropionamide,pentaerythritoltetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate),stearyl-3,5-di-tert-butyl-4-hydroxyphenylpropionate,pentaerythritoltetrakis1,3,5-tris(2,6-di-methyl-3-hydroxy-4-tert-butyl-benzyl)isocyanurate,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,1,3,5-tris(2-hydroxyethyl)isocyanurate-tris(3,5-di-tert-butylhydroxyphenylpropionate),without being limited thereto.

The heat stabilizer may be present in an amount about of 2,000 ppm orless, for example about 0.01 ppm to about 2,000 ppm, specifically about100 ppm to about 1,000 ppm in the composition for encapsulating adisplay device, based on the total amount of the photocurable monomerand the photopolymerization initiator, in terms of solid contents.Within this range, the heat stabilizer may further improve storagereliability and processability of the encapsulating composition in aliquid state.

The composition for encapsulating a display device according to theembodiments of the invention may be cured by ultraviolet ray irradiationat about 10 mW/cm² to about 500 mW/cm² for about 1 second to about 100seconds, without being limited thereto.

The composition for encapsulating a display device according to theembodiments of the invention may implement an organic layer having aplasma etch rate of about 400 nm/min or less as represented by followingEquation 1, and a surface roughness of about 2 nm or less:Plasma etch rate (nm/min)=(T0−T1)/M  [Equation 1]

in Equation 1, T0 is a thickness (unit: nm) of a sample prepared byapplying the composition for encapsulating a display device onto asubstrate by spray, followed by being subjected to ultraviolet rayirradiation at 100 mW/cm² for 10 seconds and curing the composition, T1is a thickness (unit: nm) of the above prepared sample after beingsubjected to a plasma treatment for 1 minute under the condition of ICPpower 2500 W, RF power 300 W, DC bias 200V, argon (Ar) flow rate 50sccm, pressure 10 mtorr, T0 and T1 each represents a thickness excludingthe substrate, and M is a plasma treatment time (unit: min).

Within this range, when an organic layer is formed on an organic lightemitting element, or on an inorganic layer formed on an organic lightemitting element, a plasma etch rate which represents a damage to theorganic layer during the plasma treatment is greatly reduced and anorganic layer having high plasma resistance may be provided. In someembodiments, the plasma etch rate may be about 400 nm/min or less, forexample about 10 to about 390 nm/min, specifically about 10 to about 385nm/min. When the plasma etch rate represented by above Equation 1 ismore than about 400 nm/min, damages to the organic layer may increase todeteriorate reliability of an organic light emitting element.

A surface roughness is roughness of a deposited surface measured from asurface profile after the composition for encapsulating a display deviceis deposited on a substrate. Lower surface roughness may contribute toflatten a surface of a display device.

The surface roughness of the invention may be measured by generalroughness measuring methods known to those skilled in the art. Forexample, Atomic Force Microscope (AFM) may be used. In some embodiments,surface roughness (roughness of a deposited surface) may be about 2 nmor less, for example about 0 nm to about 2 nm, about 0 nm to about 1.9nm, about 0 nm to about 1.85 nm, when measured by Atomic ForceMicroscope. When the surface roughness is 2 nm or less, an organic layerwith a flat surface may be provided, and an inorganic protective layerthat is formed after deposition of the organic layer may be deposited ina flat contour. When the surface roughness is more than about 2 nm, anorganic layer is not flattened, and an inorganic layer deposited on thesurface of the organic layer may be broken.

The composition for encapsulating a display device according to theembodiments of the invention may produce an organic layer having anoutgassing amount of about 2,000 ppm or less. Within this range,durability of a member for a device may be elongated to increasereliability. Specifically, the outgassing amount may be about 10 ppm toabout 1,000 ppm.

The outgassing amount may be measured by a conventional method. Forexample, a sample having a thickness of 5 μm is prepared by applying acomposition for encapsulating a display device onto a glass substrate,followed by being subjected to ultraviolet ray irradiation at 100 mW/cm²for 10 seconds, and curing the composition. For the specimen having athickness of 5 μm, an outgassing amount captured by heating is measuredusing an equipment TD-GC/MS (TD: JTD505III, GC/MS: Clarus 600, PerkinElmer Inc.) for a predetermined surface area (1×5 cm²) at a temperaturerange of 40° C. to 320° C. at an elevation rate of 10° C./min.

The composition for encapsulating a display device according to theembodiments of the invention may produce an organic layer having a colorcoordinate value YI of about 0.5 or less (in accordance with ASTM D1925)when measured after being cured. Within this range, the encapsulatingmaterial for a display device is transparent and transmits a light closeto a white light, which enables its application to a display device.Specifically, the organic layer may have a color coordinate value YI ofabout 0.1 to about 0.5.

The color coordinate value can be measured by a conventional method. Forexample, a sample having a thickness of 5 μm is prepared by applying thecomposition for encapsulating a display device onto a glass substrate,followed by being subjected to ultraviolet ray irradiation at 100 mW/cm²for 10 seconds, and curing the composition. For the specimen having athickness of 5 μm, transmittance of a light having a wavelength 300 nmto 800 nm is measured using a UV-visible spectrophotometer (UV-2450,SHIMADZU Corporation), and a color coordinate value YI is calculatedtherefrom (ASTM D1925).

The composition for encapsulating a display device according to theembodiments has a high total light transmittance of about 90% to about100%, specifically about 95% to about 100%, and may provide atransparent organic protection layer. The total light transmittance andhaze are measured using a hazemeter (NDH-5000, Nippon DenshokuIndustries Co., Ltd.) at a wavelength of 400 nm to 700 nm in accordancewith ASTM D1003-95.

The composition for encapsulating a display device according to theembodiments of the invention is used for applying onto a front face of alight emitting device and needs to be transparent without exhibiting acolor. When the material for encapsulating a display device exhibits acolor, the color coordinate of the light emitted from a light source ofa display device may be shifted after the light is transmitted throughthe encapsulation material in the front face to distort colors. Inaddition, as the transparency is lowered, the efficiency of the lightemitted from a front face of the display device is lowered, and thedisplay device may not be clearly visible.

The dam 140 may be formed on the non-light emitting area of thesubstrate 110, and may separate the light emitting area from thenon-light emitting area. The dam 140 is thicker than the organic lightemitting element 120. Thus, the dam 140 may protect the organic lightemitting element 120 from external moisture and/or oxygen, imparting alateral encapsulating function on the organic light emitting displaydevice, preventing the organic layer from being exposed to the outside.In addition, the dam 140 may prevent the composition for encapsulating adisplay device from spreading into outside of the light emitting area orthe substrate during formation of an organic layer. The dam 140 may alsoprevent the edge of the encapsulation layer from being thickened.

The dam 140 may block external moisture and/or oxygen, and may includean optically transparent material. Specifically, the dam 140 may includeat least one material which is included in the above described holetransporting region, the electron transporting region, and the lightemitting layer, without being limited thereto. The dam 140 may be formedwith the above material in one layer, or by stacking a plurality oflayers.

Although not shown in FIG. 1 and FIG. 2, the organic light emittingdisplay device 100 may include a driving circuit portion for driving theorganic light emitting element 120. In addition, although not shown inFIG. 1 and FIG. 2, a TFT (thin film transistor) layer and a buffer layermay be formed between the substrate 110 and the organic light emittingelement 120 in the organic light emitting display device 100. The TFTlayer may drive the organic light emitting element 120, and may includea gate line, a data line, a driving power supply line, a reference powersource line and a capacitor. Further, although not shown in FIG. 1 andFIG. 2, the organic light emitting display device 100 may furtherinclude an adhesive layer covering the encapsulation layer and the dam,and a substrate adhered to the adhesive layer and encapsulating theorganic light emitting element. The adhesive layer may be a transparentadhesive film. A material for the adhesive layer and the substrate mayinclude a conventional material known to those skilled in the art.

Hereinafter, an organic light emitting display device according to yetanother embodiment of the invention will be explained with reference toFIG. 3.

Referring to FIG. 3, an organic light emitting display device 200according to the embodiment may include a substrate 110, an organiclight emitting element 120, an encapsulation layer 130′, and a dam 140.Except that an encapsulation layer 130′ is formed instead of theencapsulation layer 130, the organic light emitting display device 200is substantially the same with the above explained organic lightemitting display device according to an embodiment of the invention.Thus, only the encapsulation layer 130′ will be explained hereinafter.

The encapsulation layer 130′ may include a first inorganic layer 131, afirst organic layer 132, and a second inorganic layer 133. Theencapsulation layer 130′ may encapsulate the organic light emittingelement 120. The encapsulation layer 130′ is additionally formed on thedam 140. Therefore, the organic light emitting display device 200 mayhave a structure in which the dam 140, the first inorganic layer 131,the first organic layer 132, and the second inorganic layer 133 aresequentially stacked on the substrate 110. Therefore, the organic lightemitting display device 200 may be protected from external moistureand/or oxygen permeation.

The first organic layer 132 is not formed continuously, and is separatedby the dam 140 in the light emitting area and the non-light emittingarea. Thus, the organic layer is not directly exposed to the outside,and external moisture and/or oxygen permeation may be suppressed.

Hereinafter, an organic light emitting display device according to yetanother embodiment of the invention will be described with reference toFIG. 4. FIG. 4 is a partial cross-sectional view of an organic lightemitting display device according to yet another embodiment of theinvention.

Referring to FIG. 4, an organic light emitting display device 300according to the embodiment may include a substrate 110, an organiclight emitting element 120, an encapsulation layer 130″, and a dam 140.Except that an encapsulation layer 130″ is formed instead of theencapsulation layer 130, the organic light emitting display device 300is substantially the same with the above explained organic lightemitting display device according to an embodiment of the invention.Thus, only the encapsulation layer 130″ will be explained hereinafter.

The encapsulation layer 130″ may include a first inorganic layer 131 anda first organic layer 132.

The first organic layer 132 is directly formed on the organic lightemitting element 120.

The first inorganic layer 131 is directly formed on the first organiclayer 132 and the dam 140. Therefore, the organic light emitting displaydevice 300 according to the embodiment may have a structure in which thedam 140 and the first inorganic layer 131 are sequentially stacked onthe substrate 110.

A portion of the first inorganic layer 131 directly formed on the firstorganic layer 132 and a portion of the first inorganic layer 131directly formed on the dam 140 are integrally formed. Thus, permeationof external moisture and/or oxygen may be suppressed.

Hereinafter, an organic light emitting display according to yet anotherembodiment of the invention will be explained with reference to FIG. 5.FIG. 5 is a partial cross-sectional view of an organic light emittingdisplay device according to yet another embodiment of the invention.

Referring to FIG. 5, an organic light emitting display device 400according to the embodiment may include a substrate 110, an organiclight emitting element 120, an encapsulation layer 130′″, and a dam 140.Except that an encapsulation layer 130′″ is formed instead of theencapsulation 130, the organic light emitting display device 300 issubstantially the same with the above explained organic light emittingdisplay device according to an embodiment of the invention. Thus, onlythe encapsulation layer 130′″ will be explained hereinafter.

The encapsulation layer 130′″ may include a first inorganic layer 131and a first organic layer 132. The encapsulation layer 130′″ is directlyformed on the organic light emitting element 120, and the encapsulationlayer 130′″ is additionally formed on the dam 140.

The first organic layer 132 is directly formed on the organic lightemitting element 120 and the dam 140. The first organic layer 132 is notformed continuously, and is separated by the dam 140 in the lightemitting area and the non-light emitting area.

The first inorganic layer 131 is directly formed on the first organiclayer 132. A portion of the first organic layer 132 directly formed onthe first organic layer 132 and a portion of the first inorganic layer131 directly formed on the dam 140 are integrally formed. Therefore, theorganic light emitting display device 400 according to the embodimentmay have a structure in which the dam 140, the first organic layer 132,and the first inorganic layer 131 are sequentially stacked on thesubstrate 110. Thus, permeation of external moisture and/or oxygen maybe suppressed.

Hereinafter, a method of manufacturing an organic light emitting displaydevice according to embodiments of the invention will be explained.

The organic light emitting display device according to the embodimentsmay include forming an organic light emitting element and a dam on asubstrate, and forming an encapsulation layer on the organic lightemitting element. Here, an inorganic layer and an organic layer may bealternately stacked in the encapsulation layer, and the organic layermay include a composition for encapsulating a display device accordingto the embodiments of the invention.

An organic light emitting element and a dam are formed on a substrate.First, an anode is formed on a substrate. A light emitting layer isformed by a dry coating such as a vacuum deposition, sputtering, plasmaplating and ion plating, or a wet coating such as spin coating, dipcoating, and flow coating, and a cathode is formed thereon tomanufacture an organic light emitting element on a substrate. The dammay be formed by stacking a predetermined above-mentioned material in anarea surrounding the organic light emitting element.

The inorganic layer is formed by a suitable vacuum process includingsputtering, evaporation, sublimation, chemical vapor deposition (CVD),plasma enhanced chemical vapor deposition (PECVD), electron cyclotronresonance plasma enhanced chemical vapor deposition (ECR-PECVD) andcombination thereof, without being limited thereto. The organic layermay be formed by vapor deposition, spin coating, printing, inkjetprinting, and/or spraying, without being limited thereto. A mask may beused in forming the inorganic layer and the organic layer.

Mode for Invention

The following examples, comparative examples and test example, theconfiguration and effect of the invention will be described in detail.However, the examples, comparative examples and test examples are notintended to be limited by to the spirit and scope of the invention butonly be provided for the purpose of illustrating examples andcomparative examples and test examples to aid the understanding of theinvention.

Preparation Example 1

In a 3,000 ml reactor equipped with a cooling tube and a stirrer, 300 mlof dichloromethane (Sigma Aldrich Corporation) was placed, and 200 g of4-hydroxybutyl acrylate (Shin Nakamura Chemical Co., Ltd.) and 168 g oftriethylamine were added, followed by cooling the temperature of theflask to 0° C., and adding dropwise a solution of 278 g ofp-toluenesulfonyl chloride (Sigma-Aldrich Corporation) dissolved in 500ml of dichloromethane, for 2 hours while stirring. After stirring foradditional 5 hours, the remaining solvent was removed by distillation.The obtained compound 300 g was added to 1,000 ml of acetonitrile (SigmaAldrich Corporation), and 220 g of potassium carbonate (Sigma AldrichCorporation) and 141 g of 2-phenylphenol were added, followed bystirring at 80° C. Residual solvent and reaction residue were removed toobtain a compound of Formula 5 (molecular weight 296.36) having a purityof 93% as determined by HPLC.

Preparation Example 2

In a 2,000 ml flask equipped with a cooling tube and a stirrer, 600 mlof dichloromethane (Sigma Aldrich Corporation) was placed, and 58.8 g of2-hydroxyethylmethacrylate (Sigma Aldrich Corporation) and 52.2 g oftriethylamine (Sigma Aldrich Corporation) were added while stirring at0° C., followed by slowly adding 100 g of triphenylchloromethane (SigmaAldrich Corporation). After raising the temperature to 25° C., themixture was stirred for 4 hours. After removing dichloromethane bydistillation under reduced pressure, 124 g of a compound of Formula 6having a purity of 97% as determined by HPLC was obtained using a silicagel column.

Preparation Example 3

In a 2,000 ml flask equipped with a cooling tube and a stirrer, 800 mlof acetonitrile (Fisher Scientific) was placed, and 180 g of potassiumcarbonate (Sigma Aldrich Corporation) and 108 g of acrylic acid wereadded while stirring at 0° C., followed by slowly adding 150 g of4,4′-bis(chloromethyl)biphenyl (Tokyo Chemical Industry Co., Ltd.).After raising the temperature to 70° C., the mixture was stirred for 12hours. After removing acetonitrile by distillation under reducedpressure, 177 g of a compound of Formula 7 having a purity of 97% asdetermined by HPLC was obtained using a silica gel column.

Preparation Example 4

In a 3,000 ml reactor equipped with a cooling tube and a stirrer, 300 mlof dichloromethane (Sigma Aldrich Corporation) was placed, and 200 g of2-hydroxyethyl acrylate (Shin Nakamura Chemical Co., Ltd.) and 168 g oftriethylamine were added, followed by cooling the temperature of theflask to 0° C., and adding dropwise a solution of 278 g ofp-toluenesulfonyl chloride (Sigma-Aldrich Corporation) dissolved in 500ml of dichloromethane, for 2 hours while stirring. After stirring foradditional 5 hours, the remaining solvent was removed by distillation.The obtained compound 300 g was added to 1,000 ml of acetonitrile (SigmaAldrich Corporation), and 220 g of potassium carbonate (Sigma AldrichCorporation) and 141 g of 2-phenylphenol were added, followed bystirring at 80° C. Residual solvent and reaction residue were removed toobtain a compound of Formula 8 (molecular weight 296.36) having a purityof 93% as determined by HPLC.

Preparation Example 5

In a 3,000 ml reactor equipped with a cooling tube and a stirrer, 300 mlof dichloromethane (Sigma Aldrich Corporation) was placed, and 400 g of2-hydroxyethyl acrylate (Sigma Aldrich Corporation) and 168 g oftriethylamine were added, followed by cooling the temperature of theflask to 0° C., and adding dropwise a solution of 278 g ofp-toluenesulfonyl chloride (Sigma Aldrich Corporation) dissolved in 500ml of dichloromethane, for 2 hours while stirring. After stirring foradditional 5 hours, the remaining solvent was removed by distillation.The obtained compound 300 g was added to 1,000 ml of acetonitrile (SigmaAldrich Corporation), and 220 g of potassium carbonate (Sigma AldrichCorporation) and 141 g of 2,2′-biphenol (Sigma Aldrich Corporation) wereadded, followed by stirring at 80° C. Residual solvent and reactionresidue were removed to obtain a compound of Formula 9 (molecular weight382.41) having a purity of 91% as determined by HPLC.

Preparation Example 6

In a 1,000 ml reactor equipped with a cooling tube and a stirrer, 100 gof benzene thiol, 200 ml of dichloromethane (Sigma Aldrich Corporation),and 8.2 g of zinc perchlorate (Sigma Aldrich Corporation) were placed,followed by stirring, and slowly adding dropwise 109.05 g of styreneoxide (Sigma Aldrich Corporation) to carry out a reaction at roomtemperature. After 4 hours, an inorganic material was removed usingwater and dichloromethane, and the residual solvent was evaporated toobtain a first product 192 g. In a 2,000 ml reactor, 150 g of the firstproduct, 70.31 g of triethylamine (Sigma Aldrich Corporation), and 500ml of dichloromethane were stirred at 0° C., followed by slowly addingdropwise 64.84 g of acryloyl chloride (Sigma Aldrich Corporation) tocarry out a reaction. After completion of adding dropwise, thetemperature was slowly raised to room temperature, followed by stirringfor additional 4 hours. After completion of the reaction, the mixturewas purified with n-hexane (Daejung Chemicals and Metals CO., Ltd.) toremove salts and impurities, followed by distillation of the residualsolvent under reduced pressure to obtain a compound of Formula 10(molecular weight 284.37) having a purity of 85% as determined by HPLC.

Details of components used in Examples and Comparative Examples are asfollows.

(A) A monomer without an aromatic hydrocarbon:

(a1) dodecanediol dimethacrylate (Sartomer Company Inc.)

(a2) triethylene glycol dimethacrylate (BASF Corporation)

(a3) trimethylolpropane triacrylate (BASF Corporation)

(a4) 2-dimethylaminoethyl acrylate (ACROS Organics)

(B) A monomer including substituted or non-substituted at least twophenyl group:

(b1) monomer of Preparation Example 1

(b2) monomer of Preparation Example 2

(b3) monomer of Preparation Example 3

(b4) monomer of Preparation Example 4

(b5) monomer of Preparation Example 5

(b6) monomer of Preparation Example 6

(b7) CP-011 (4-cumylphenoxyethyl acrylate, Hannong Hwasung Inc.)

(b8) Bisphenol A dimethacrylate (Sigma Aldrich Corporation)

(b9) BPM-102 (Bisphenol A ethoxylated (10) dimethacrylate, HannongHwasung Inc.)

(b10) Bisphenol F ethoxylated (2) diacrylate (Sigma Aldrich Corporation)

(C) A photopolymerization initiator: a phosphorus initiator (DarocurTPO, BASF Corporation)

Example 1

90 parts by weight of (a1), 10 parts by weight of (b1), and 5 parts byweight of (C) were placed in a 125 ml brown polypropylene bottle, andthe mixture was stirred for 3 hours with a shaker to prepare acomposition for encapsulating a display device of Example 1.

Examples 2 to 25 and Comparative Examples 1 to 15

Each composition for encapsulating a display device was prepared as inthe same manner with Example 1, except that each component was used asin Table 1 to Table 4.

Property Evaluation

(1) Plasma etch rate (%): Each of the compositions for encapsulating adisplay device of Examples and Comparative Examples was applied on a525±25 μm thick silicon wafer by spraying, followed by curing byultraviolet ray irradiation at 100 mW/cm² for 10 seconds to prepare a 5μm thick organic layer specimen. The prepared specimen was subjected toa plasma treatment for 1 minute with an argon gas using an ICP dryetcher (Plasma lab system 133, Oxford instruments) under the conditionof ICP power 2500 W, RE power 300 W, DC bias 200V, Ar flow 50 sccm,pressure 10 mtorr. A plasma etch rate was calculated according to thefollowing Equation 1 by measuring a thickness (T0) of an organicprotective layer prior to being subjected to a plasma treatment and athickness (T1) of an organic protective layer after being subjected to aplasma treatment, and the results are shown in Table 1 to Table 4. Thethicknesses T0 and T1 each represents a thickness excluding a thicknessof a substrate, and M is a plasma treatment time (min).Plasma etch rate (nm/min)=(T0−T1)/M  [Equation 1]

(2) Surface roughness (nm): A specimen prepared as in above (1) wasplaced on an atomic force microscope (XE-100, Park Systems), and surfaceroughness of the specimen was measured under the condition of Head Mode:contact Mode. PSPD Display Window: A+B→1V, A−B→−500 mV˜+500 mV.

(3) Color coordinate value YI (ASTM D1925): Transmittance of a specimenprepared as in above (1) was measured using an analysis equipmentUV-visible spectrophotometer (UV-2450, SHIMADZU Corporation) at awavelength of 300 nm to 800 nm, and then a color coordinate value YI(ASTM D1925) was calculated.

(4) Light transmittance (%): Total light transmittance of a specimenprepared as in above (1) was measured using a haze meter (NDH-5000,Nippon Denshoku Industries Co., Ltd.) at a wavelength of 400 nm to 700nm according to ASTM D1003-95.

TABLE 1 Unit: Parts by Examples weight 1 2 3 4 5 6 7 8 9 10 11 12 13 (A)(a1) 90 80 70 60 60 60 — — — — — 60 60 (a2) — — — — — — 60 50 — — — — —(a3) — — — — — — 20 — 30 30 — — — (a4) — — — — — — — 20 30 30 60 — — (B)(b1) 10 20 30 40 — — 20 30 — — — — — (b2) — — — — 40 — — — 40 — 20 — —(b3) — — — — — 40 — — — 40 20 — — (b4) — — — — — — — — — — — 40 — (b5) —— — — — — — — — — — — 40 (b6) — — — — — — — — — — — — — (b7) — — — — — —— — — — — — — (b8) — — — — — — — — — — — — — (b9) — — — — — — — — — — —— — (b10) — — — — — — — — — — — — — (C) 5 5 5 5 5 5 5 5 5 5 5 5 5 Plasmaetch 385 364 357 331 328 342 353 341 320 336 326 325 342 rate (nm/min)Surface 1.24 1.33 1.52 1.83 1.86 1.65 1.44 1.64 1.87 1.73 1.74 1.83 1.54roughness (nm) Color 0.41 0.41 0.41 0.41 0.4 0.42 0.41 0.41 0.42 0.420.41 0.41 0.41 coordinate value YI Light 99 99 99 99 99 99 99 99 99 9999 99 99 transmittance (%)

TABLE 2 Unit: Parts by Examples weight 14 15 16 17 18 19 20 21 22 23 2425 (A) (a1) 60 — — — — — 60 60 60 60 — — (a2) — 50 — 60 — 30 — — — — 70— (a3) — — 30 — 70 — — — — — — 70 (a4) — 20 30 — — 30 — — — — — — (B)(b1) — — — — — — — — — — — 20 (b2) — — — — — — — — — — — — (b3) — — — 20— — — — — — — — (b4) — 30 — — 20 — 35 35 35 35 — — (b5) — — 40 20 — 20 —— — — 20 — (b6) 40 — — — 10 20 — — — — — — (b7) — — — — — — 5 — — — — —(b8) — — — — — — — 5 — — 10 — (b9) — — — — — — — — 5 — — — (b10) — — — —— — — — — 5 — 10 (C) 5 5 5 5 5 5 5 5 5 5 5 5 Plasma etch 360 340 335 338348 328 323 320 320 321 354 352 rate (nm/min) Surface 1.74 1.64 1.681.53 1.74 1.52 1.83 1.82 1.83 1.82 1.63 1.64 roughness (nm) Color 0.430.42 0.41 0.41 0.42 0.42 0.42 0.42 0.42 0.42 0.42 0.42 coordinate valueYI Light 100 99 99 99 99 99 99 99 99 99 99 99 transmittance (%)

TABLE 3 Unit: Parts by Comparative Examples weight 1 2 3 4 5 6 7 8 (A)(a1) 100 50 60 95 — — — — (a2) — — 40 — 40 — — 50 (a3) — — — 5 — 20 — —(a4) — — — — — 20 40 — (B) (b1) — 50 — — 60 — — — (b2) — — — — — — 30 20(b3) — — — — — 60 30 — (b4) — — — — — — — 30 (b5) — — — — — — — — (b6) —— — — — — — — (b7) — — — — — — — — (b8) — — — — — — — — (b9) — — — — — —— — (b10) — — — — — — — — (C) 5 5 5 5 5 5 5 5 Plasma etch 418 327 610820 280 314 308 312 rate (nm/min) Surface 1.14 2.16 1.24 1.22 3.42 2.433.13 2.24 roughness (nm) Color 0.41 0.41 0.41 0.41 0.45 0.46 0.44 0.41coordinate value YI Light 99 99 99 99 99 99 99 99 transmittance (%)

TABLE 4 Unit: Comparative Examples Parts by weight 9 10 11 12 13 14 15(A) (a1) — — 50 — — 30 — (a2) — — — — 30 — — (a3) 30 — — 50 — — 50 (a4)— 40 — — 20 20 — (B) (b1) — — — — — — 30 (b2) — — — — — — — (b3) — — — —— — — (b4) 40 — — — — — — (b5) 30 30 — — 30 — — (b6) — 30 — 30 — 30 —(b7) — — 50 20 — — — (b8) — — — — 20 — — (b9) — — — — — — 20 (b10) — — —— — 20 — (C) 5 5 5 5 5 5 5 Plasma etch rate 296 310 324 318 287 320 322(nm/min) Surface roughness 3.35 3.14 2.54 2.43 3.65 2.44 2.42 (nm) Colorcoordinate 0.41 0.43 0.46 0.45 0.48 0.45 0.45 value YI Light 99 100 9999 95 99 99 transmittance (%)

As shown in Table 1 to Table 4, each specimen in Examples has a lowplasma etch rate, good plasma resistance, and good flatness which has asurface roughness of 2 nm or less. Further, each specimen in Exampleshas a color coordinate value YI (ASTM D1925) of 0.50 or less and hightransmittance. Thus, a transparent organic layer may be provided. On theother hand, each specimen in Comparative Examples has a problem forhaving a high etch rate or high surface roughness as compared with thatof Examples.

While certain embodiments of the invention have been illustrated anddescribed, it is understood that various modifications, changes,alterations, and equivalent embodiments can be made by those skilled inthe art without departing from the spirit and scope of the invention, asdefined in the following claims. It should be understood that variousmodifications, changes, alterations, and equivalent embodiments can bemade by those skilled in the art without departing from the spirit andscope of the invention.

The invention claimed is:
 1. An organic light emitting display devicecomprising: a substrate comprising a light emitting area, and anon-light emitting area disposed outside of the light emitting area; atleast one organic light emitting element formed on the light emittingarea; an encapsulation layer encapsulating the organic light emittingelement; and a dam formed on the non-light emitting area, wherein theencapsulation layer has a structure in which at least one inorganiclayer and at least one organic layer are alternately stacked one aboveanother, and the organic layer comprises a composition for encapsulatinga display device, the composition for encapsulating a display devicecomprising a photocurable monomer and a photopolymerization initiator,the photocurable monomer comprising a monomer without an aromatichydrocarbon; and a monomer of following Formula 1 comprising substitutedor non-substituted at least two phenyl groups, the photocurable monomercomprising about 5 wt % to about 45 wt % of the monomer comprisingsubstituted or non-substituted at least two phenyl groups and about 55wt % to about 95 wt % of the monomer without an aromatic hydrocarbon:

wherein in Formula 1, A is a hydrocarbon comprising substituted ornon-substituted at least two phenyl groups, or a hetero atom-containinghydrocarbon comprising substituted or non-substituted at least twophenyl groups, Z¹ and Z² are each independently a compound of followingFormula 2, a and b are each independently an integer of 0 to 2, and a+bis an integer of 1 to 4:

wherein in Formula 2, * is a portion connected to a carbon atom of A inFormula 1, X is a single bond, 0 or S, Y is a substituted ornon-substituted straight chain alkylene group having 1 to 10 carbonatoms, or a substituted or non-substituted alkoxylene group having 1 to20 carbon atoms, R¹ is hydrogen or an alkyl group having 1 to 5 carbonatoms, and c is 0 or
 1. 2. The organic light emitting display deviceaccording to claim 1, wherein one organic layer has a thickness of about0.2 μm to about 15 μm.
 3. The organic light emitting display deviceaccording to claim 1, wherein the inorganic layer comprises at least oneof silicon oxide, silicon nitride, silicon oxynitride, ZnSe, ZnO, Sb₂O₃,Al₂O₃, In₂O₃, or SnO₂.
 4. The organic light emitting display deviceaccording to claim 1, wherein the inorganic layer is additionally formedon the dam.
 5. The organic light emitting display device according toclaim 4, wherein the inorganic layer comprises a first inorganic layerand a second inorganic layer, and wherein the organic light emittingdisplay device has a structure in which the dam, the first inorganiclayer, and the second inorganic layer are sequentially stacked on thesubstrate.
 6. The organic light emitting display device according toclaim 4, wherein the inorganic layer comprises a first inorganic layer,and wherein the organic light emitting display device has a structure inwhich the dam and the first inorganic layer are sequentially stacked onthe substrate.
 7. The organic light emitting display device according toclaim 1, wherein the encapsulation layer is additionally formed on thedam.
 8. The organic light emitting display device according to claim 7,wherein the inorganic layer comprises a first inorganic layer and asecond inorganic layer, and the organic layer comprises a first organiclayer, and wherein the organic light emitting display device has astructure in which the dam, the first inorganic layer, the first organiclayer, and the second inorganic layer are sequentially stacked on thesubstrate.
 9. The organic light emitting display device according toclaim 7, wherein the inorganic layer comprises a first inorganic layer,and the organic layer comprises a first organic layer, and wherein theorganic light emitting display device has a structure in which the dam,the first organic layer, and the first inorganic layer are sequentiallystacked on the substrate.
 10. The organic light emitting display deviceaccording to claim 8, wherein the first organic layer in the lightemitting area is separated from the first organic layer in the non-lightemitting area by the dam.
 11. The organic light emitting display deviceaccording to claim 1, wherein the monomer comprising substituted ornon-substituted at least two phenyl groups comprises at least one ofmono(meth)acrylate and di(meth)acrylate.
 12. The organic light emittingdisplay device according to claim 11, wherein the mono(meth)acrylatecompound is represented by following Formula 3:

wherein in Formula 3, R² is hydrogen or a methyl group, R³ is asubstituted or non-substituted straight chain alkylene group having 1 to10 carbon atoms, or a substituted or non-substituted alkoxylene grouphaving 1 to 20 carbon atoms, and R⁴ is a hydrocarbon comprisingsubstituted or non-substituted at least two phenyl groups, or a heteroatom-containing hydrocarbon comprising substituted or non-substituted atleast two phenyl groups.
 13. The organic light emitting display deviceaccording to claim 11, wherein the di(meth)acrylate compound isrepresented by Formula 4:

wherein in Formula 4, R⁵ and R⁹ are each independently hydrogen or amethyl group, R⁶ and R⁸ are each independently a substituted ornon-substituted straight chain alkylene group having 1 to 10 carbonatoms, or a substituted or non-substituted alkoxylene group having 1 to20 carbon atoms, and R⁷ is a hydrocarbon comprising substituted ornon-substituted at least two phenyl groups, or a hetero atom-containinghydrocarbon comprising substituted or non-substituted at least twophenyl groups.
 14. The organic light emitting display device accordingto claim 1, wherein the monomer comprising substituted ornon-substituted at least two phenyl groups comprises one of4-(meth)acryloxy-2-hydroxybenzophenone,ethyl-3,3-diphenyl(meth)acrylate, benzoyloxyphenyl(meth)acrylate,bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate,bisphenol F di(meth)acrylate, ethoxylated bisphenol F di(meth)acrylate,4-cumylphenoxyethyl(meth)acrylate, ethoxylatedbisphenylfluorenedi(meth)acrylate, 2-phenylphenoxyethyl(meth)acrylate,2,2′-phenylphenoxyethyldi(meth)acrylate,2-phenylphenoxypropyl(meth)acrylate,2,2′-phenylphenoxypropyldi(meth)acrylate,2-phenylphenoxybutyl(meth)acrylate,2,2′-phenylphenoxybutyldi(meth)acrylate,2-(3-phenylphenyl)ethyl(meth)acrylate,2-(4-benzylphenyl)ethyl(meth)acrylate,2-phenyl-2-(phenylthio)ethyl(meth)acrylate,2-(triphenylmethyloxy)ethyl(meth)acrylate,4-(triphenylmethyloxy)butyl(meth)acrylate,3-(biphenyl-2-yloxy)butyl(meth)acrylate,2-(biphenyl-2-yloxy)butyl(meth)acrylate,4-(biphenyl-2-yloxy)propyl(meth)acrylate,3-(biphenyl-2-yloxy)propyl(meth)acrylate, 2-(biphenyl-2-yloxy)propyl(meth)acrylate, 4-(biphenyl-2-yloxy)ethyl(meth)acrylate,3-(biphenyl-2-yloxy)ethyl (meth)acrylate,2-(4-benzylphenyl)ethyl(meth)acrylate, 4,4′-di((meth)acryloyloxymethyl)biphenyl, 2,2′-di(2-(meth)acryloyloxyethoxy)biphenyl,or mixtures thereof.
 15. The organic light emitting display deviceaccording to claim 1, wherein the hydrocarbon comprising substituted ornon-substituted at least two phenyl groups, or the heteroatom-containing hydrocarbon comprising substituted or non-substituted atleast two phenyl groups comprises a substituted or non-substitutedbiphenyl group, a substituted or non-substituted triphenylmethyl group,a substituted or non-substituted terphenyl group, a substituted ornon-substituted biphenylene group, a substituted or non-substitutedterphenylene group, a substituted or non-substituted quarterphenylenegroup, a substituted or non-substituted 2-phenyl-2-(phenylthio)ethylgroup, a substituted or non-substituted 2,2-diphenylpropane group, asubstituted or non-substituted diphenylmethane group, a substituted ornon-substituted cumylphenyl group, a substituted or non-substitutedbisphenol F group, a substituted or non-substituted bisphenol A group, asubstituted or non-substituted biphenyloxy group, a substituted ornon-substituted terphenyloxy group, a substituted or non-substitutedquarterphenyloxy group, or a substituted or non-substitutedquinquephenyloxy group.
 16. The organic light emitting display deviceaccording to claim 1, wherein the monomer comprising substituted ornon-substituted at least two phenyl groups has a molecular weight ofabout 100 g/mol to about 1,000 g/mol.
 17. The organic light emittingdisplay device according to claim 1, wherein the monomer without anaromatic hydrocarbon comprises at least one of mono(meth)acrylatecomprising an amine group, di(meth)acrylate comprising a substituted ornon-substituted alkylene group having 1 to 20 carbon groups,di(meth)acrylate comprising an ethylene oxide group, tri(meth)acrylatecomprising an ethylene oxide group, or trimethylolpropanetri(meth)acrylate.
 18. The organic light emitting display deviceaccording to claim 1, wherein the photocurable monomer is formed only ofat least one element selected from the group consisting of C, H, O, N orS.
 19. The organic light emitting display device according to claim 1,wherein the photopolymerization initiator comprises at least oneselected from the group consisting of a triazine initiator, anacetophenone initiator, a benzophenone initiator, a thioxanthoneinitiator, a benzoin initiator, a phosphorus initiator, and an oximeinitiator.
 20. The organic light emitting display device according toclaim 1, wherein the composition for encapsulating a display devicefurther comprises a heat stabilizer.